Pressure leakage gauge



Aug. 20, 1940. R. L. BRADFORD 2,212,466

PRESSURE LEAKAGE GAUGE Filed Aug. 15, 1938 INVENTORZ ROBERT L. BRADFORD ATTORNEY retencedne i. 20,1940

UNITED STATES PATENT OFFICE rasssuar. LEAKAGE GAUGE ,RobertL. Bradford, sen Francisco; Calif.

Application August ,15, 1938, Serial No. 224,987

4 Claims.

This invention relates to improvementsin pressure leakage gauges and, more particularly, to motorstats.

Among. the objects of the invention is to pro- 5 vide a meter for indicating the condition of pressure sealing means, with special reference gines, pumpstanks, and the like. Another object is to establish a calibrated standard oi measurement, and give a definite l0 visual reading of pressure losses without computation.

Another object is to measure pressure losses in exact terms. I Another object is to indicate the location and the causeof such losses. A further object is to give a full reading on a single dial pressure gauge;

to en- Otherobjects and advantages will appear as the description progresses. m -In this specification and the accompanying drawings, the invention is disclosed in its adaptation to internal combustion engines. It is to be understood, however, that it is notlimited to this form, because it may be embodied in modill' iicatlons within the purview of the claims following' the description.

" In the one sheet of drawings:

A= motorstat constructedin accordance with this invention is shown in vertical section in op- 30' era'ti've relation to a similar section oi the upper portion of a conventional internal combustion The end cap it is screwed on to the end III of the center block and sealed by the compressed gasket I9. This can is recessed to receive the strainer forced therein. The outer end of the cap is threaded to receive the reducer 2|, having I the=hose coupling 22' of the hose 22 screwed thereon; The opposite end of the'hose has a similar coupling connecting it to the source of air pressure in the service pipe 23. It is usual to provide a self closing service valve at this 19 point, not shown, so that the hose 22 may be readily attached and detached.

A similar cap 24 is threaded on the opposite end ll of the center block and sealed off from the reservoir l2 by the flexible diaphragm I5 and 1 the interposed chafing ring 26. A pressure regulator is assembled within the cap 24- and consists of the expansion spring 21, having the convex head 28 bn one end and bearing against the inner face of the diaphragm 25, and the concave 20 6 head 29 'on its opposite end to receive the tapered end of the thumb screw 3|! threaded in the end of the cap 24.- Thisscrew has the flat head 3| to facilitate manual turning-of the screw to vary the tension of the spring 21 against the diamotor, the pressure gauge being in its balanced operative condition.

In detail, the construction illustrated in th '3 drawing comprises thewater jacketed cylinder I,

' having the piston l reciprocal therein. This piston is provided with. the pressure sealing rings 3.

v The usual intaketand-exhaust valves, such as 4, r are located adjacent the cylinder.

The water jacketed head- I is bolted to the cyl-'- I .inder block with the intermediate gasket 0, and has the combustion chamber I overhanging the cylinder, opening and the intake and exhaust valves. The spark plug opening I is provided 5 "in the cylinder head and leads into thecom'bus All of which is 'conventionah tlon chamber.

practice. c

The motorstat comprises the cylindrical center block 9, threaded on each end at II,- II.. .This

- 5o block-is center bored from one end to form" the reservoir II, and counterbored to form the con- .centricchamber ll, with the-chamtered rim at M. The opposite end ll of the block is counter-' sunk to forms spring socket at. I I, surrounding us the inlet I'I into'the-chamber It.

phragrn 25. p

The end of the chamber is is sealed by the plug 32 screwed thereinto and having the polygonal head. and the tapered shoulder fitting the chamfer ll. This plug has the annular valve seat 35 and is axially drilled to pass the stem- 36 on the valve head 31 with a surface of yielding material in operative relation to-the valve seat 35. The spring 38' expanding between the socket l6 and the valve head 31 normally urges'the valve 35 into closed position. The protruding end 01' this valve stem 36 has the convex head 3! bearing against the diaphragm 2t. v p

The center block 0 has the by-pass 40 leading into the reservoir II. The reducing nipple ll 40 isscrewed into'the side of the block 9 and has the restricted opening 42 leading from the bypass The side outlet 43 open to the center bore H in the nipple ll has the hose 5 attached thereto which is connected to the pressure gauge 45 gauge case It has the hook II adapted to suspend the gauge at any convenient place, such as the brace rod a: of an automobile radiator.

The tubular sleeve 55 is threaded on the outer end of the nipple 4| and has the internal yielding valve seat 51 intermediate its length. The sliding plunger 58 has theannular valve 59 in operative relation to the valve seat 51. The expansion spring 60 has its inner end seated in the nipple 4| and its other end bearing against the valve 59 to maintain the valve normally seated. The hollow plunger 58 has the by-pass 6| which is exposed within the chamber 62 when the valve 59 is unseated.

The outer end of the sleeve 56 has the yielding valve seat 63 therein. The annular valve 84 is screwed on the end of the plunger in operative relation to the valve seat 53. The extended hollow stem 65 of this valve has the tapered rubber adapter 66 flxed thereon and adapted to enter and seal the spark plug hole 8 while the air service from 23 is flowing into thecombustioncham-.

ber 1. Y

' The invention operates substantially as fol- .lows: The air pressure, in excess of fifty pounds per square inch, flows from the service pipe 23 and the intermediate conduits past the valve 31 into the reservoir 52. As the pressure rises in the reservoir l2, the diaphragm 25 moves outward allowing the valve 31 to close under the tension of the spring 3Bpreventing admission of additional air into the reservoir. D

From the reservoir l2, the air flows through the by-pass 40 and the restricted opening 42 into the chamber 44 and thence to the pressure gauge. The pressure unbends the tube 41 and moves the arrow out of itsinitial position as-shown inthe system rises to the point that the arrow 5| is brought to zero" on the dial 52. This is equivalent to a pressure of approximately fifty pounds in the reservoir l2. There is an equilibrium between the spring 38 and the air pressure against the diaphragm 25 and the regulating spring 21. Should the pressure in thereservoir I2 commence to fall, the spring 21 will overcome the reduced pressure on the opposite side of the diaphragm 25 and open the valve 31 to'restore the reservoir pressure to the predetermined value.

With the piston 2 at the top of its stroke and the valves at 4 closed, the operator graspsthe caps i8, 24 and forces (the adaptor 56 into thespark plug hole 8. This unseats the valve 59, closes the valve 53, 54and admits air from the chamber 44, through the by-pass SI and the hollow plunger 58 into the combustion chamber 1.

If the piston rings 3, the valves 4, andthe gasket '5 allow only the tolerated leakage permissible I in a motor in excellent condition, the pressure in the chamber 44 will rise very nearly;to the pressure in the reservoir I2 since the restricted opening 42 will supply air as rapidly as its leaks from the combustion chamber. 1 with very little.

pressure diflerential between the reservoir l2. and the chamber 44; The pressure gauge arrow 5! will consequently continue to register substantially"zero indicating zero leakage in excess-of that normally tolerated and consequently one.

hundred per cent eiflciency in the engine pressure sealing.

Should there be excess leakage at the" pressure sealing elements 3, 4, 6, the pressure in the chamber 44 will drop until the pressure difference in the reservoir l2 and the chamber 44 becomes sufficiently great to cause air to issue through the restricted opening 42 at the rate it is leaking from g the motor combustion chamber 1. The greater the leakage from the combustion chamber, the lower will be the pressure in the chamber 44. The drop in pressure in the chamber 44 also proportiona-lly bleeds the pressure from the flexible tube 41 in the pressure gauge causing the arrow 5! to advance from zero to the graduation on the dial 52 indicating the relative degree of leakage and inefliciency in the pressure sealing means.

By slowly moving the piston 2 downward, any change registered on the gauge will indicate at what point in the stroke the piston rings decrease in their ability to seal the pressure. The manner in which the reading of the gauge varies enables the detection of various conditions such as the cylinder walls being worn out of round, scored, tapered, or otherwise imperfect.

After testing the total leakage from the combustion chamber 1, oil is introduced into the cylinder i on top of the piston 2 to create a perfect .seal at this point. The reading of the gauge will then indicate the condition of the valves at 4. Gasket leakage will usually be audible externally, or, by 'bubbles in the radiator of water cooling system. Cracks in the walls between cylinders will usually beindicated by hissing in the adjacent cylinder not under pressure. This and other leak locating tests are well known to those skilled in the art. v

Having thus described this invention, what I claim and desire to secure by Letters Patent is:

1. A leakage gauge including a block having a pressure reservoir therein; a spring seated inlet valve intermediate said reservoir and ,a source of fluid pressure; a pressure regulator in operative relation to said valve and reservoir; a sleeve projecting from said block and communicating with said reservoir through a restricted opening; a pressure gauge connected to said sleeve; an outlet valve in-said sleeve "having a hollow plunger stem projecting beyond said'sleeve and slidable 'relative thereto for opening and closing said valve; an external valve on said stem in spaced relation to a valve seat on said sleeve and adapted to be closed when said outlet is opened; and a tapered adapter or yielding material on -said external valve.

2. A leakage gauge including a block having a pressure reservoir therein; an inlet valve intermediate a source of fluid pressure and said reservoir; a pressure regulator in operative relation to en't meansurging the valve controlled by said 7 stem into closedposition; means on said stem adapted to engage an opening in the container to be tested; and a valve surrounding said stem and interposed between said sleeve and said con-- tainer engaging means and adapted to be closed when the valve inside the sleeve is opened.

3. A leakage. gauge including a blockhaving a 7 pressure reservoir therein; a spring seated valve in an inlet intermediate a source of fluid pressure and said reservoir; a pressure regulator in operative relation to said valve and reservoir; a sleeve communicating with said reservoir through a restricted opening; a pressure gauge connected to said sleeve; a valve seat within said sleeve; a hollow plunger stem slidable in said sleeve and projecting therefrom; a valve on said stem arranged to cooperate with said valve seat and adapted to be opened by moving said stem inwardly to provide communication between said sleeve and the interior of said stem; resilient means in said sleeve urging said stem outwardly; means on said stem adapted to engage an opening in the container to be tested; and a valve surrounding said stem and interposed between said sleeve and said container engaging means and adapted to be closed when the valve inside the sleeve is opened.

.4. A leakage tester having a hollow center block with a chamber therein; alined end caps fixed to opposite sides of said block; a hollow sleeve having a calibrated opening and projectinglaterally from said block; means for delivering fluid pressure through one of said caps to said block; a pressure regulator in the other of said caps; a valve in said block cooperating with said pressure regulator to admit pressure to said chamber; .inner and outer valve seats on the outer end of said sleeve;- a hollow valve stem projecting from said sleeve and having a valve cooperating with said inner seat; a tapered resilient adapter on said stem having a'valve cooperating with said outer seat to close when the valve cooperating with said inner seat is opened;

ROBERT L. BRADFORD. S0 

